Contents 1. INTRODUCTION… … … .… … … … … … … … … … … … … … … … … … … .… . 2 1.1 OVERVIEW… … … … … .… … … … … … … … … … … … … … … … … … 2 1.2 MAIN FEATURES… .… … … … … … … … … … … … … … … … … … .… . 2 2. TECHNICAL SPECIFICATIONS… … … … … … … … … … … … .… .… .… … . 3 2.1 ELECTRICAL CHARACTERISTICS… … … … … … … … … … … ...… … 3 2.2 EVIRONMENTAL CHARACTERISTICS… … … … … … … … … … .… … 4 2.3 PHYSICAL CHARACTERISTICS… … … … … … … … … … … … … ..… .. 4 3. MECHANICAL DIMENSIONS… … … … … … … … 3.
1. Introduction 1.1. Overview GPS module ZX4125/ZX4125P (patch on top) is a high sensitivity ultra low power consumption cost efficient, compact size; plug & play GPS module board designed for a broad spectrum of OEM system applications. The GPS module receiver will track up to 16 satellites at a time while providing fast time-to-first-fix and 1Hz navigation updates.
2. Technical Specifications 2.1. Electrical Characteristics 2.1.1 General Frequency C/A code Channels L1, 1575.42 MHz 1.023 MHz chip rate 16 2.1.2 Sensitivity Tracking Acquisition -152dBm typ -139dBm typ 2.1.3 Accuracy Position Velocity Time 7 meters CEP (90%) horizontal, SA off. 0.1 meters/second 1 microsecond synchronized to GPS time 2.1.4 Datum Default Other WGS-84 Support different datum by request 2.1.
2.1.8 Serial Port Electrical interface Protocol message Default NMEA one full duplex serial communication, TTL interface NMEA-0183, version 3.0 optional. GGA, GSA, GSV, RMC and VTC. 9600 baud rate, 8 bits data, 1 start, 1 stop, no parity. (GSA & GSV is 3sec output 1msg, option baud rate: 4800,19200, 38400) 2.1.9 Time-1PPS Pulse (optional) Level TTL Pulse duration 100ms Time reference at the pulse positive edge Measurements Aligned to GPS second, +-1 microsecond 2.1.
Mechanical Dimensions 3.1. ZX4125 Pin 1 Pin 11 Pin 17 Pin 1 Pin 17 Pin 11 Pin 1 2 3 4 5 6 7 8 9 10 Name GPIO [4] NC (MODE) NMEA TX NMEA RX NC(WAKE UP) Reset VBAT GND VDD GPIO [0] Pin 11 12 13 14 15 16 17 18 19 Name DSUMUX DSUEN DSUBRE DSUTX DSURX DSUACT RF GND RF IN RF GND *Pin Assignment please refers to the Table 3-1.
3.2. ZX4125P-4 Pin 1 Pin 17 Pin 1 2 3 4 5 6 7 8 9 10 Pin 11 Name GPIO [4] NC (MODE) NMEA TX NMEA RX NC(WAKE UP) Reset VBAT GND VDD GPIO [0] Pin 11 12 13 14 15 16 17 18 19 Name DSUMUX DSUEN DSUBRE DSUTX DSURX DSUACT RF GND RF IN RF GND *Pin Assignment please refers to the Table 3-1.
ZX4125P-2 Pin 1 Pin 11 Pin 17 Pin 1 2 3 4 5 6 7 8 9 10 Name GPIO [4] NC (MODE) NMEA TX NMEA RX NC(WAKE UP) Reset VBAT GND VDD GPIO [0] Pin 11 12 13 14 15 16 17 18 19 Name DSUMUX DSUEN DSUBRE DSUTX DSURX DSUACT RF GND RF IN RF GND *Pin Assignment please refers to the Table 3-1.
3. Pin Assignment of Connector 3.1. Serial Interface Communication to the ZX4125 is provided via a serial interface. A 10-pin 1.27mm whole connector is used. The pin out is shown in Table 4-1. Pin 6 (Reset) is the active-low reset input. The ZX4125 always requires a reset at power-up, or it will not start properly. An optional onboard reset circuit can be provided. A reset forces the ZX4125 processor to reboot, but will not influence other parameters such as hot or cold start.
3.2. Debug Interface A dedicated pin out (in form of test points) is provided on the board to give the possibility to connect the ZX4125 debug unit. The debug port is intended to be used only during the development stage and to download the firmware at factor setup. It is not meant to be used by the customers unless they want to develop or modify the SW of the ZX4125 module. The debug port includes the signals required by the debug system unit (DSU).
4. Applications ZX4125 module board receiver is a high performance, ultra low power consumption, plug &play product. These applications are as follow. l Car Navigation l Wrist Watch l Solar Operated Device l Marine Navigation l Fleet Management l AVL and Location-Based Services l Radar detector with GPS function l Hand-Held Device for Personal Positioning and Navigation l Ideal for PAD, Pocket PC and Other Computing Devices at GPS Application 5.
Appendix A: Other Electrical Specifications Table A-1 Absolute Maximum Ratings Parameter Symbol Min Power Supply Voltage VDD -0.3 Input Pin Voltage VIN -0.3 Output Pin Voltage VOUT -0.3 Reset Pin Voltage Vreset -0.3 Storage Temperature TSTG -40 Back-up Voltage BAT Table A-2 Operating Conditions Parameter Symbol Min Typ Power Supply Voltage VDD 3 3.3 Input Pin Voltage VIN 2.
Appendix B: Reference Design 12
Appendix C: Software Specification ZX4125 NMEA Protocol The ZX4125 software is capable of supporting the following NMEA message formats NMEA Message Prefix Format Direction SGPGGA(1)* GPS fix data. Out SGPGLL Geographic position Latitude / Longitude. Out SGPGSA(3)* GNSS DOP and actives satellites Out SGPGSV(3)* Satellites in view. Out SGPRMC(1)* Recommended minimum specific GNSS data. Out SGPVTG(1)* Velocity and track over ground. Out SGPZDA Date and time.
General NMEA Format The general NMEA format consists of an ASCII string commencing with a ‘$’ character and terminating with a sequence. NMEA standard messages commence with ‘GP’ then a 3-letter message identifier. NemeriX specific messages commence with $PNMRX followed by a 3 digit number. The message header is followed by a comma delimited list of fields optionally terminated with a checksum consisting of an asterix ‘*’ and a 2 digit hex value representing the checksum.
Corrections Diff int 4 4 0000. Checksum *xx (0) 3 3 2 digits. Message 2 2 ASCII 13, ASCII 10. Reference Corrections terminator $GPGLL This message transfers Geographic position, Latitude, Longitude, and time. The $GPGLL message structure is shown below: Field Format Min chars Max chars Notes Message ID $GPGLL 6 6 GLL protocol header. Latitude Float 1,2.1 3,2.4 Degree * 100 + minutes. N/S Indicator Char 1 1 N=north or S=south. Longitude Float 1,2.1 3,2.
$GPGSA This message transfers DOP and active satellites information. The $GPGSA message structure is shown below: Field Format Min chars Max chars Notes Message ID $GPGSA 6 6 GSA protocol header. Mode Char 1 1 M Manual, forced to operate in selected mode. An Automatic switching between modes. Mode Int 1 1 1 Fix not available. 2 2D position fix. 3 3D position fix. Satellites Used Int 2 2 SV on channel 1. Satellites Used Int 2 2 SV on channel 2. … . .. .. ..
$GPGSV This message transfers information about satellites in view. The $GPGSV message structure is shown below. Each record contains the information for up to 4 channels, allowing up to 12 satellites in view. In the final record of the sequence the unused channel fields are left blank with commas to indicate that a field has been omitted. Field Format Min chars Max chars Notes Message ID $GPGSV 6 6 GSA protocol header.
$GPRMC This message transfers recommended minimum specific GNSS data. The $GPRMC message format is shown below. Field Format Min chars Max chars Notes Message ID $GPRMC 6 6 RMC protocol header. UTC Time hhmmss.sss 1,2,2.1 2,2,2.3 Fix time to 1ms accuracy. Status char 1 1 A Data Valid. V Data invalid. Latitude Float 1,2.1 3,2.4 Degrees * 100 + minutes. N/S Indicator Char 1 1 N=north or S=south. Longitude Float 1,2.1 3,2.4 Degrees * 100 + minutes.
$GPVTG This message transfers Velocity, course over ground, and ground speed. The $GPVTG message format is shown below. Field Format Min chars Max chars Notes Message ID $GPVTG 6 6 VTG protocol header. Course (true) Float 1.1 3.2 Measured heading in degrees. Reference Char 1 1 T = true heading. Course (magnetic) Float 1.1 3.2 Measured heading (blank). Reference Char 1 1 M = magnetic heading. Speed Float 1.1 4.2 Speed in knots. Units Char 1 1 N = knots.
$GPZDA This message transfers UTC Time and Date. Since the latency of preparing and transferring the message is variable, and the time does not refer to a particular position fix, the second precision is reduced to 2 decimal places. The $GPZGA message format is shown below. Field Format Min chars Max chars Notes Message ID $GPZDA 6 6 ZDA protocol header. UTC time hhmmss 2,2,2.2 2,2,2.2 00000000.00 to 235959.99 UTC day dd 2 2 01 to 31, day of month. UTC month mm 2 2 01 to 12.
Examples: $PNMRX100,0,4800,0*xx: sets the UART baud rate to 4800 bps and no parity. $PNMRX101, Navigation Initialization This message is sent to initialize navigation parameters to speed up initial acquisition time. The $PNMRX101 message format is shown below. Field Format Min chars Max chars Notes Message ID $PNMRX101 6 8 PNMRX101 protocol header.
$PNMRX103, NMEA rate control This message is being sent to enable or to disable the output of an NMEA message and to determine its output rate. The sequence of the output sequence is determined by the $PNMRX107 message. The $PNMRX103 message format is shown below. The rate of each message can individually be set. If ‘0’ is used, the output of the message is skipped (according to the message sequence).
$PNMRX104, LLA navigation initialization This message enables the receiver to be initialized using LLA data to speed up satellite acquisition. The first 4 values defining the position (if used) must be all present in the message. Otherwise the whole massage is considered invalid. Field Format Min chars Max chars Notes Message ID $PNMRX104 8 8 PNMRX104 protocol header. (Under dev.) Latitude Float 1,2.1 3,2.4 Degrees * 100 + minutes. (Under dev.) N/S Indicator Char 1 1 N=north or S=south.
$PNMRX106, Datum This message defines the conversion model used for mapping the ECEF coordinates into the LLA ones. The default transformation uses WGS84 approximation. The transformation method can be changed into one using a reference Ellipsoid combined with a local datum, to obtain a specific estimation of the local earth geometry. Once the datum has been changed it will be applied to all LLA data, including the LLA navigation initialization Data.
$PNMRX107, Messages rate control This message is sent to set the automatic update rate, and to configure which messages will be automatically output, it is also sent from the node to report which messages are currently configured for automatic transmission. The $PNMRX107 message format is shown below. This message can be used to enable and disable multiple messages by including up to 4 message codes and associated fields in each $PNMRX107 message.
$PNMRX108, NMEA message sequence This message is used to set the sequence used to output the NMEA messages. All messages in the list are set to be output with a default output rate. The messages that are not included are disabled. Once the sequence is defined, individual settings for the messages can be changed by means of the $PNMRX103 message. This message is supported also in a variable length format, where only the necessary fields are used.
$PNMRX110, Fix Settings This message is used to set various settings and masks which control how the software will behave in relationship to the satellites in view, for example a mask can be set for the minimum satellite elevation, minimum SNR etc. The message consists of a varying number of fields depending on the number of masks to be set. Each mask setting consists if a mask identifier and new value pair. The $PNMRX110 message format is shown below.
$PNMRX111, Software reset This message is used to reset the systems. If the message is sent without parameters the receiver reboots according to the fix procedure (hot, warm or cold) configured with the PNMRX101 or PNMRX104 messages. A second parameter can optionally be used to specify which actions are executed after the reset. If the last bit field is set to ‘1’, then the actions are repeated permanently at each reset, until this bit is cleared.
$PNMRX112, Power Mode Control This message is used to configure the operating modes of the receiver. Low power modes can be activated and configured. Low power mode starts to work only after the receiver has a complete and up to date almanac and it can produce the fix. Field Format Min chars Max chars Notes Message ID $PNMRX112 6 8 PNMRX112 protocol header.
$PNMRX300, Almanac Data Transfer This message format is used to transfer the almanac data between nodes; it uses a packed hexadecimal format to transfer almanac data for each of the available SV’s. Since the Almanac data is large and can take time to transfer over a slow serial interface, the data is divided into individual messages for each of the SV’s.
$PNMRX301, Ephemeris Data Transfer This message format is used to transfer the ephemeris data between nodes; it uses a packed hexadecimal format to transfer ephemeris data for each of the available SV’s. Since the Ephemeris data is large and can take time to transfer over a slow serial interface, the data is divided into individual messages for each of the SV’s.
PNMRX301 message 2 field list Field Format width scale units Notes Message ID $PNMRX301 8 PNMRX301 protocol header. Satellite Vehicle Id Int 2 Decimal satellite vehicle id from 1 to 32. Subframe Id Int 1 Subframe number 2. Iode Hex 2 8 bits, lower 8 bits of matching iodc. -5 Crs Hex 4 2 Motion difference Hex 4 2-43 Meters 16 bit signed integer. Semi- 16 bit signed integer. circles/sec Mean anomaly Hex 8 2-31 -29 Semi- 32 bit signed integer.
PNMRX301 message 3 field list Field Format width Message ID $PNMRX301 8 PNMRX301 protocol header. Satellite Vehicle Id Int 2 Decimal satellite vehicle id from 1 to 32. Subframe Id Int 1 Subframe number 3. Cic Hex 4 2-29 8 2 -31 -29 Omega zero Hex scale units Notes Radians 16 bit signed integer. Semi- 32 bit signed integer. circles Cis Hex 4 2 I Zero Hex 4 2-31 -5 radians 16 bit signed integer. Semi- 32 bit signed integer.
$PNMRX302, Ionospheric correction Field Format width scale units Notes Message ID $PNMRX302 8 PNMRX301 protocol header. Satellite Vehicle Id Int 2 Decimal satellite vehicle id from 1 to 32. a0 Hex 2 2-30 a1 Hex 2 2-27 a2 Hex 2 2-24 a3 Hex 2 2-24 ß0 Hex 2 211 ß1 Hex 2 214 ß2 Hex 2 216 ß3 Hex 2 216 Checksum *xx (0) 3 2 digits. Message terminator 2 ASCII 13, ASCII 10.
$PNMRX304, GPS Constellation Health Field Format Min chars Max chars Notes Message ID $PNMRX304 8 8 PNMRX110 protocol header. Health Code Char TBD TBD SV health code if ? 0. Health Code Char TBD TBD SV health code if ? 0. Checksum *xx (0) 3 3 2 digits. Message 2 2 ASCII 13, ASCII 10. terminator $PNMRX600, Report Software Version By sending the $PNMRX600*00 string to the receiver, the version of the software is output.
PNMRX603 message 1 Field Format Min chars Max chars Notes Message ID $PNMRX603 8 8 PNMRX603 protocol header. Message Nb Int 1 1 1 Ionospheric Hex 2 2 Ionospheric correction a0 coefficient. Hex 2 2 Ionospheric correction a1 coefficient. Hex 2 2 Ionospheric correction a2 coefficient. Hex 2 2 Ionospheric correction a3 coefficient. Hex 2 2 Ionospheric correction ß0 coefficient. Hex 2 2 Ionospheric correction ß1 coefficient.
NMRX603 message 2 Field Format Min chars Max chars Notes Message ID $PNMRX603 8 8 PNMRX603 protocol header. Message Nb Int 1 1 2 MaxPDOP Float MaxHDOP Float Invalid Sv Hex 8 8 Min CNO Float Min Elevation Float Max TM Int 2 2 Max Sv for fix Int 2 2 Checksum *xx (0) 3 3 2 digits. Message 2 2 ASCII 13, ASCII 10. terminator PNMRX603 message 3 Field Format Min chars Max chars Notes Message ID $PNMRX603 8 8 PNMRX603 protocol header.
PNMRX603 message 4 Field Format Min chars Max chars Notes Message ID $PNMRX603 8 8 PNMRX603 protocol header.
